1. Field of the Invention
The present invention relates generally to a modular cross-arm support structure for supporting a plurality of power transmission lines on a support structure, such as a vertical pole. More specifically, the present invention provides a utility insulated cross-arm which can be installed quickly and easily, and which provides a plurality of electrical insulators in a fixed spaced relation to ensure adequate separation between the transmission lines carried on the structure.
2. Description of Related Art
Since the earliest use of power transmission lines, there has been a recognition of the need to support the lines above the ground to provide isolation between the lines and the environment. One of the most common arrangements for supporting transmission lines comprises a plurality of electrical insulators mounted on wooden cross-arms attached to vertical wooden poles. Such structures are generally constructed in a sequential manner with a first work crew mounting the wooden poles in the ground, followed by a second work crew which secures the cross-arms to the poles and mounts the electrical insulators on the cross-arms.
Wooden support structures of the type described above have a number of shortcomings, both with regard to durability and with regard to ease of construction. The wooden poles and cross-arms are subject to deterioration from exposure to the environment and from internal defects in the materials.